This invention relates to a ceramic fiber block for lining a high temperature furnace, which is composed of a plurality of rectangularly contoured laminated ceramic fiber layers successively bonded or bound together and includes a welding stud which is made of a metal to be welded to a furnace wall by electrical welding and disposed between two ceramic fiber layers centrally positioned in the ceramic fiber layers in the proximity of the rear end surfaces of the rectangularly contoured layers on the side of the relevant furnace wall and perpendicularly to the rear end surfaces, and a pair of piercing rods connected through an anchor bar to the welding stud and piercing the whole ceramic fiber layers.
With such a ceramic fiber block for lining a high temperature furnace, in general, as shown in FIG. 1 after the ceramic fiber block 1 has abutted against a furnace wall 2 made of a metal, an electrode rod 5 is extended from a guide sleeve 4 so as to contact a welding stud 6 by means of a stud welding machine 3 so that the welding stud 6 is connected to the furnace wall 2 by electrical welding. During such a welding operation the welding stud 6 is urged with its melted distal end against the furnace wall 2 so as to be welded to the furnace wall 2 and at the same time piercing rods 8 piercing a plurality of ceramic fiber layers are pulled toward the furnace wall 2 through curved anchor bars 7 wound about the piercing rods 8 to cause prestresses in the ceramic fiber block. As a result, the ceramic fiber block 1 is firmly fixed to the furnace wall 2. Thereafter, the electrode rod 5 is removed together with the guide sleeve 4 from the ceramic fiber block 1.
With the conventional ceramic fiber block for lining a high temperature furnace, in the case of an electric (resistance heating) furnace, after the ceramic fiber block has been fixed to a furnace wall, a pair of upper and lower ceramic rods 9 are embedded in the ceramic fiber block 1 in the vicinity of its front surface on the opposite side of the furnace wall so as to extend in parallel with piercing rods and then a plurality of S-shaped ceramic hangers 10 are forced into the ceramic fiber block 1 so as to be hanged on the ceramic rods 9 at a required predetermined interval in separate and troublesome operations as shown in FIG. 2. After these operations, corners of meandering or zigzag-shaped heating elements 12 are hanged on the exposed hook ends 10A of the S-shaped hangers 10 through ceramic washers 11, respectively.
In another conventional example of the ceramic fiber block, after base studs have been previously fixed to a furnace wall by welding, a ceramic fiber block is mounted on these base studs. Then, ceramic insulators are connected to the ceramic fiber block for finally arranging heating elements by hanging them on the ceramic insulators.
With such hitherto used ceramic fiber blocks for lining high temperature furnaces, however, in case of electric furnaces, the operation for mounting hangers for supporting heating elements is carried out in a separate step after the ceramic fiber blocks have been fixed to the furnace walls, with resulting low working efficiency.